@article{Grujic:63116,
      author        = "Grujic, Jelena and Gracia-Lázaro, Carlos and Milinski,
                       Manfred and Semmann, Dirk and Traulsen, Arne and Cuesta,
                       José A. and Moreno, Yamir and Sánchez, Angel",
      title         = "{A comparative analysis of spatial Prisoner's Dilemma
                       experiments: Conditional cooperation and payoff
                       irrelevance}",
      year          = "2014",
}